This study investigates the longitudinal course of alcohol problems at one- and three year follow-up intervals in representative samples of untreated and treated problem drinkers. The Center's prior work in the Community Epidemiology Laboratory (CEL) has mapped the prevalence and community response to alcohol problems across a wide range of health and social services. This work has highlighted the important role that the formal (general health, mental health, drug treatment, criminal justice, and welfare agencies) and informal (the influences of family, friends, colleagues, religious and mutual help groups) community response plays in how alcohol problems are handled in communities. At the same time longitudinal studies have pointed to certain robust predictors of reduced consumption and problems over time, such as initial consumption and problem levels, socio-demographic characteristics, and psychiatric and drug use comorbidities. The study integrates these histories of alcohol studies follows four groups of problem drinkers at one- and three-year time points: those admitted to 1) public sector (N=300), 2) health maintenance organizations (N=300), and 3) private indemnity (N=300) alcohol treatment programs at baseline, and 4) a probability sample of untreated problem drinkers in the general population of th same community (N=665). Baseline data collection of these samples is currently underway, sponsored by NIAAA (R01AA09750). We hypothesize that different patterns of informal and formal community responses are important factors in explaining the course of drinking, such as differences in the course of problems for women and men, and among different ethnic groups. The study first focuses on examining change in untreated problem drinkers in the general population, and then on comparing the experience of problem drinkers in the three major sectors of treatment (public, private, HMO) with untreated problem drinkers in the general population who have no insurance, private indemnity insurance, and HMO coverage. The aims of the proposed research focus on studying longitudinal change in drinking behavior.